The production of alcohols, particularly fatty alcohols, is of considerable interest in the industry.
The catalytic hydrogenolysis of carboxylic acid esters is an interesting way of producing such alcohols but, up to now, it was restrained by the disadvantages of the catalysts known in the art:
the catalysts comprising essentially mixed copper and chromium oxides, either doped or not, require operation under high pressure, nearly always higher than 20 MPa, and at a temperature ranging from 250.degree. to 350.degree. C.; PA1 the catalysts comprising essentially transition metals deposited on a carrier require operation at a temperature lower than 250.degree. C. and preferably than 200.degree. C. in order to limit the degradation of the alcohol products to hydrocarbons; thereby requiring operating pressures generally higher than 10 MPa in order to obtain good selectivities at an acceptable conversion rate.
More recently, in the European patent application No. EP-A-95 408 a catalyst has been proposed which is formed by the association of rhodium with, for example, tin, deposited on such a carrier as, for example, silica or alumina. By using this catalyst, the operating conditions may be relatively mild (temperature lower than about 280.degree. C. and pressure lower than about 8 MPa) with good yields of alcohols. However, the high cost and the limited availability of rhodium are serious disadvantages and, accordingly, the applicant has continued searching in order to find a catalyst giving good yields of alcohols under relatively mild operating conditions without the disadvantages of rhodium use.